1. Field of the Invention
This invention relates to a red phosphor and a method for producing the red phosphor. It also relates to a white light source, an illumination device and a liquid crystal display that make use of the red phosphor.
2. Description of Related Art
A white light source, formed by a plurality of light emitting diodes, is used as an illumination device and as a backlight of a liquid crystal display. Such white light source is known in which a phosphor of cerium-containing yttrium-aluminum-garnet, referred to below as YAG:Ce, is arranged on a light emitting surface of a blue light emitting diode, sometimes abbreviated herein to blue LED.
There is also known such a white light source in which green and red sulfide phosphors are arranged on a light emitting side of a blue LED. See for example a Patent Document 1. In addition, such an arrangement is proposed in which a combination of fluorescent substances is arranged on a light emitting surface of an LED radiating blue to purple color or blue color. The combination of the fluorescent substances is a mixture at preset proportions of a phosphorescent material composed of a crystal of CaAlSiN3 that forms a solid solution with Mn or Eu and another phosphorescent material. See for example Patent Document 2.